Know your target audience
Sales ads are the last step in most marketing campaigns. This means that you have already determined how to get this ad in front of someone that would likely purchase it.
In refelction, think about how you feel if receive an ad for something you were acutall thinking of purchasing. It is a much better feeling than something not targeted to your needs.
Retail are not ads meant for reading so don’t waste time on heavy content. Focus on the sale by listing Top Benefits, Price, Guarantees… short essential terms.